The invention relates to an apparatus and system for recovering waste heat from refrigeration systems.
Conventional refrigeration systems circulate a refrigerating fluid which is evaporated within the refrigerating compartment to absorb heat which is transferred outside the compartment when the gas is condensed back to its liquid state. In most homes and businesses having such refrigeration systems there is also a need for hot water. Many proposals have been made in the past to use the waste heat from the refrigeration system to in whole or part heat water for domestic or industrial use. For example, the patent to McGraw, U.S. Pat. No. 1,937,288, shows a system of this type in which hot refrigeration liquid passes through a heat exchanger to heat water in a tank. The patent to Johnson, U.S. Pat. No. 4,199,955, describes another system of this type. A great variety of such waste recovery systems have in the past been proposed.
The present invention relates to an improved and practical system which is economical, can be installed with minimum difficulty, is reliable, and is designed to supplement an existing hot water system. According to the present invention a heat exchanger is inserted into a conventional refrigerating system between the compressor and the condenser. A water line passes through the heat exchanger between an inlet which receives cold water and an outlet which supplies the heated water to a small holding tank which can be located immediately adjacent to the refrigeration system. The holding tank is coupled to a larger storage tank, for example, a conventional home water heater, by a check valve so that the heated water from the holding tank is transferred to the larger storage tank whenever water is withdrawn from the larger tank.
A pump is connected between the outlet of the holding tank and the inlet of the heat exchanger for circulating the water through the heat exchanger. A temperature sensor is preferably provided to detect the temperature of the gases from the compressor so that the pump is operated only when there is heat to be transferred to the water. A heat sensor is also preferably provided at the holding tank to turn off the pump when the water has reached its maximum temperature.
The system can be used with a single refrigerator, air conditioner of the like or can be used in an apartment building or industrial establishment with the hot water from the various holding tanks being supplied to a single central hot water heater or storage tank.
Other objects and purposes of the invention will be clear from the following brief description of the drawings.